Communication systems are regularly utilized in modern society through which to communicate data pursuant to the effectuation of a communication service. Data communicated pursuant to the effectuation of the communication service is originated at a communication source and is sent upon a communication channel for delivery to a communication target.
At a minimum, a communication system is formed of a first communication station that forms, or is coupled to, the communication source and a second communication station that is coupled to, or forms, the communication target. The communication stations are connected by way of a communication channel upon which the data is communicated by the first communication station to the second communication station. The first communication station that sends the data is sometimes referred to as a sending station. And, the second communication station that receives the data is sometimes referred to as a receiving station.
A communication-station pair in which each of the communication stations thereof forms both a sending station and a receiving station permits two-way communication services to be effectuated. That is to say, the communication stations are each capable of both sending and receiving data. Telephonic communications and communications in which closed-loop feedback is utilized are exemplary of communication services that include communication stations capable of both sending and receiving data.
Successive generations of communication systems have been developed and deployed to take advantage of technological advancements. Technological advancements, when applied to communication systems, are generally applied in manners to increase the data throughput rates at which the data is communicated, the accuracy by which the data is communicated, or the manner by which the data can be communicated.
An exemplary type of communication system is a radio communication system. In a radio communication system, the communication channels upon which data is communicated are defined upon radio links that extend between the communication stations of the radio communication system. Wireline connections, conventionally required in a wireline communication system through which to connect the communication stations, and upon which communication channels are defined, are obviated. Various advantages are provided to radio communication systems in which the need for such wireline connections is obviated. In addition to reduced infrastructure costs associated with the installation of a radio communication system, a radio communication system also provides for communication mobility. That is to say, one, or more, of the communication stations between which data is communicated pursuant to effectuation of a communication service is permitted movement.
Technological advancements related to processing technologies also are applied to communication systems. Technological advancements that pertain to processing technologies, when applied to communication systems, generally permit increased amounts of data to be processed in decreased amounts of time. Modern data processing techniques permit significant amounts of data to be stored and operated upon. Radio communication systems, as well as other types of communication systems, are regularly utilized by which to transport the data that is to be stored and operated upon through the use of data processing techniques.
Various types of communication devices have been developed that perform, in addition to performance of communication functions, various data processing operations. Additional communication services and associated applications shall likely continue to be developed that require communication devices to implement new data processing and new communication technologies.
Personal digital assistants (PDAs) are exemplary of communication devices that are available, and regularly utilized by which to effectuate communication services and to operate upon data. The devices are typically of relatively small dimensions, i.e., of dimensions that permit their hand carriage by a user.
Typically, personal digital assistants contain storage locations for storing data forming one or more databases. During operation of a personal digital assistant, the user of the personal digital assistant, or analogous such processing device, selectably retrieves the data stored at the databases maintained thereat. The data that forms the database is usually formatted to form, e.g., data records formed of one or more data fields. The data fields are populated with data that is stored at the database. Upon selection of particular data records, or fields thereof, by the user, the data is retrieved from the database and displayed, or otherwise made available, to the user. Processing operations, such as sorting operations are also selectably initiated by the user. Sorting, or other processing, of the data is performable. Also, the user of the device is able further selectably to change, add to, or delete from, the data stored at the database.
To ensure that the data stored at the portable device is not irretrievably lost in the event of malfunction of, or other problem with, the portable device, the data is copied, i.e., backed up, at a separate storage device. Once suitably backed up, the back up copy is retrieved, if necessary, to access the data or to re-store the data at the portable device. Conventional personal digital assistants, for instance, sometimes provide for the back up of the data maintained at the databases thereof at a computer workstation or analogous device that contains a storage memory depository. Back up operations by which to store a back up copy of a database maintained at the personal digital assistant conventionally utilizes a fixed cable to which a wireline connection is formed between the portable device and the device that contains the storage memory depository. Once the data is stored at the storage memory depository, the back up copy is available for subsequent access thereto, if necessary.
The back up copy of the database is a complete copy of the data stored at the portable device only for so long as the data maintained at the respective devices are not altered. When, as is conventionally the case, asynchronous changes to the database maintained at the portable device or at the back up copy causes the data at the respective locations no longer to be in match with one another. And, therefore, any asynchronous change to the database or its back up copy results in data content dissimilarities therebetween.
In order to place the database maintained at the portable device, and its copy, back into match with each other, the database and its back up copy must be synchronized. Synchronization operations are performed, for instance, during subsequent back up operations, at timed intervals, or upon detection of a change to a data record at either of the locations. During synchronization operations, data stored at the respective locations are compared together. And, responsive to the comparisons, data found to be out-of-match with one another is identified. Appropriate change to the data is then effectuated to place the data back in match with one another.
Some portable devices make use of a radio air interface by which, amongst other things, to back up and synchronize data stored at the databases. Data back up operations and data synchronization operations that are performed by way of a radio air interface are, however, more problematical than operations performed by way of a conventional wireline connection. Bandwidth limitations, for instance, limit the communication capacity that can be made available for the back up and synchronization operations. And, the use of conventional techniques, predicated upon the use of wireline connections rather than a radio air interface, as a general rule, are prohibitively bandwidth consumptive when applied to a system in which such operations are performed by way of a radio air interface. Additionally, the information that is transported upon the radio air interface must be carefully selected so that the information needed to perform the synchronization operation can be efficiently effectuated.
Any manner by which to provide better for the back up and synchronization of data by way of a radio air interface would therefore be advantageous.
It is in light of this background information related to synchronization of data contents of databases by way of a radio air interface that the significant improvements of the present invention have evolved.